The Harry Potter author told a young fan known as Kate to 'talk to someone close to her' after she tweeted Rowling saying she 'wouldn't mind if I didn't wake up in the morning'. Rowling responded immediately with soothing words, telling her: 'I would mind very much.'

Katy Finn, 21, from Buckinghamshire, says her OCD drove her to 'opt out' of reality in favour of creating a world she could control. She invented a social group, even adding fake contacts to her phone.